Sailom's Philosophy

Discussing philosophical or scientific issues and their possible applications in politics. Monitoring daily world news headlines and commenting them.

Tuesday, October 31, 2006

Hubble telescope will get upgrade - BBC News

http://news.bbc.co.uk/2/hi/science/nature/6102690.stm

Servicing will extend the life of Hubble into the next decade

Nasa chief Mike Griffin says shuttle astronauts will be sent to service the Hubble Space Telescope.

The orbiting observatory has astounded astronomers and the public alike with its amazing pictures of the cosmos, but it will soon fail unless serviced.

Dr Griffin told Nasa employees that recent modifications to the shuttle launch system meant he felt it was now safe to send a crew to work on Hubble.

The mission, which will use the shuttle Discovery, should launch in 2008.

It's a great day for science, a great day for discovery, a great day for inspiration

Maryland Senator Barbara Mikulski

"We are going to add a shuttle servicing mission - to the Hubble space telescope - to the shuttle's manifest to be flown before [the orbiter] retires," Dr Griffin told an audience at the Goddard Space Flight Center in Maryland where the Hubble programme is managed.

Without servicing, the observatory is not expected to last more than two or three years.

Its batteries and gyroscopes, which are used to point the telescope, are degrading and they will now be replaced.

The shuttle crew will also install two new instruments: the Wide Field Camera 3 (WFC3), and the Cosmic Origins Spectrograph (COS). The new instruments will improve significantly Hubble's ability to see distant, faint objects in the early Universe.

Haven of safety

The servicing mission should extend Hubble's orbital lifetime to at least 2013, by which time Nasa will be getting close to launching a successor: the James Webb Space Telescope.

[an error occurred while processing this directive]Dr Griffin's decision reverses that of his predecessor, Sean O'Keefe, who cancelled the planned visit in the wake of the Columbia shuttle disaster in 2003.

The orbiter's heat shield had been damaged during launch and the ship was destroyed as it returned through the atmosphere for landing 16 days later.

Mr O'Keefe had implemented a safe-haven policy for subsequent shuttle crews, which meant if their orbiters became damaged in a similar way they could stay on the International Space Station until rescued.

A Hubble servicing mission was a casualty of this policy as shuttles do not carry sufficient fuel to move between the orbits of the observatory and the station.

Dr Griffin's green light will now require Nasa to prepare an alternative rescue strategy if Discovery finds it has sustained catastrophic damage on the climb to orbit.

Record of discovery

This would involve sending up another shuttle to attempt a ship-to-ship transfer of astronauts.

"There are very small odds that we would have a problem on ascent for which the remedy would be a launch-on-need shuttle - a rescue shuttle," explained Dr Griffin.

"But against the very small probability that that could occur [we] have made the decision that we will carry that rescue option in the manifest; and that that rescue mission will consist of a shuttle waiting on the other pad from which we launch the Hubble mission."

The news of a servicing mission will be greeted with jubilation by astronomers worldwide. The multi-billion-dollar mission has made a remarkable contribution to our understanding of the origin and evolution of the Universe.

Hubble has obtained the deepest views of the cosmos, finding high-interest objects for other observatories to investigate in detail.

Its studies of the Universe's expansion early in its mission dramatically refined the best estimates for the age of the cosmos. Its pictures have also produced definitive proof for the existence of black holes and confirmed theories of planetary formation.

Scientists expect an upgraded Hubble to continue making groundbreaking discoveries.

Maryland Senator Barbara Mikulski, who has campaigned for a servicing mission, called Tuesday "an exceptional day".

"It's a great day for science, a great day for discovery, a great day for inspiration; because that's one of the things Hubble has meant to so many people," she told the Goddard meeting.

Global Warming Could Devastate Economy - Live Science

http://www.livescience.com/environment/061030_ap_gw_economy.html

By Thomas WagnerAssociated Pressposted: 30 October 200611:03 am ET

LONDON (AP) ─ Unchecked global warming will devastate the world economy on the scale of the world wars and the Great Depression, a British government report said Monday, as the country launched a bid to convince doubters that environmentalism and economic growth can coincide.

Prime Minister Tony Blair said unabated climate change would eventually cost the world the equivalent of between 5 percent and 20 percent of global gross domestic product each year. He called for “bold and decisive action'' to cut carbon emissions and stem the worst of the temperature rise.

“It is not in doubt that, if the science is right, the consequences for our planet are literally disastrous,'' he said. “This disaster is not set to happen in some science fiction future many years ahead, but in our lifetime.''

The report emphasized that global warming can only be fought with the cooperation of major countries such as the United States and China, and represents a huge contrast to the Bush administration's wait-and-see global warming policies.

Sir Nicholas Stern, the senior government economist who wrote the report, said that acting now to cut greenhouse gas emissions would cost about 1 percent of global GDP each year. He recommended a “low-carbon global economy'' through measures including taxation, regulation of greenhouse gas emissions and carbon trading.

“That is manageable,'' he said. “We can grow and be green.''

President Bush kept America ─ by far the biggest emitter of carbon dioxide and other gases blamed for global warming ─ out of the Kyoto international treaty to reduce greenhouse gases, saying the pact would harm the U.S. economy. The international agreement was reached in Kyoto, Japan, in 1997 and expires in 2012.

Blair, Bush's top ally in the Iraq war, has indicated that Bush's policies on climate change are unacceptable.

The prime minister made that clear when he signed an agreement this year with California Gov. Arnold Schwarzenegger to develop new technologies to combat the problem. The measure imposed the first emissions cap in the United States on utilities, refineries and manufacturing plants in a bid to curb the gases that scientists blame for warming the Earth.

Treasury Chief Gordon Brown, who is expected to replace Blair as prime minister next year, announced Monday that former Vice President Al Gore, who has emerged as a powerful environmental spokesman, would advise the British government on climate change.

Blair and the report also said that no matter what Britain, the United States and Japan do, the battle against global warming cannot succeed without deciding when and how to control the greenhouse gas emissions by such fast-industrializing giants as China and India.

“Our actions over the coming decades could create risks of major disruption to economic and social activity, later in this century and in the next, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20th century,'' he said.

The report said at current trends average global temperatures will rise by 3.6 to 5.4 degrees within the next 50 years or so, and the earth will experience several degrees more of warming if emissions continue to grow.

It said such warming could have effects such as melting glaciers, rising sea levels, declining crop yields, drinking water shortages, higher death tolls from malnutrition and heat stress, and widespread outbreaks of malaria and dengue fever. Developing countries often would be the hardest hit.

The report acknowledged that its predictions regarding GDP relied on sparse data about high temperatures and developing countries, and placed monetary values on human health and the environment, “which is conceptually, ethically and empirically very difficult.''

Brown said Britain would lead the international effort against climate change, establishing “an economy that is both pro-growth and pro-green.'' He called for Europe to cut its carbon emissions by 30 percent by 2020 and 60 percent by 2050.

Under the 1997 Kyoto accord, 35 industrialized nations committed to reducing emissions by an average 5 percent below 1990 levels by 2012.

But Britain is one of only a handful of industrialized nations whose greenhouse gas emissions have fallen in the last decade and a half, the United Nations said Monday.

The U.N. said Germany's emissions dropped 17 percent between 1990 and 2004, Britain's by 14 percent and France's by almost 1 percent.

Overall, there was a 2.4 percent rise in emissions by 41 industrialized nations from 2000 to 2004, mostly because former Soviet-bloc countries, whose emissions declined in their economic downturn of the 1990s, increased emissions during the recent four-year period by 4.1 percent.

The British government is considering new “green taxes'' on cheap airline flights, fuel and high-emission vehicles.

Monday, October 30, 2006

Simple living - Wikipedia

http://en.wikipedia.org/wiki/Simple_living

Simple living (similar but not identical to voluntary simplicity or voluntary poverty) is a lifestyle individuals may pursue for a variety of motivations, such as spirituality, health, or ecology. Others may choose simple living for reasons of social justice or a rejection of consumerism. Some may emphasize an explicit rejection of "westernized values", while others choose to live more simply for reasons of personal taste, a sense of fairness or for personal economy.

Simple living as a concept is distinguished from the simple lifestyles of those living in conditions of poverty in that its proponents are consciously choosing to not focus on wealth directly tied to money or restrictive, cash-based economics. Although asceticism may resemble voluntary simplicity, proponents of simple living are not all ascetics. The term "downshifting" is often used to describe the act of moving from a lifestyle of greater consumption towards a lifestyle based on voluntary simplicity.

Brown pledge to lead climate effort - The Guardian

Gordon Brown is to promise to lead the international effort against climate change as a major Government report predicts irreversible economic damage unless the world acts now.

The warning comes after it emerged that ministers are considering a raft of new eco-taxes designed to curb harmful greenhouse gas emissions.

Sir Nicholas Stern, in his long-awaited review of the economic costs of global warming, will say there is still time to avoid the worst effects of climate change.

But without urgent global action, the world risks major disruptions which would be "difficult or impossible to reverse".

Mr Brown, who commissioned the report, will seize on its findings to demand a concerted international push to reduce carbon emissions.

The Chancellor, who has recruited former US Vice President Al Gore as an international environment adviser, will pledge to lead the global response.

"The truth is, we must tackle climate change internationally, or we will not tackle it at all," he will insist.

"I can say that Britain will lead this global effort."

The Stern review, billed as the most comprehensive assessment ever of the financial consequences of climate change, will say that the up-front price of tackling global warming will pay off in growth over the long-term.

Sir Nicholas sets the cost of reducing emissions at 1% of GDP - a figure which will rise massively in the years ahead if action is not taken now.

Saturday, October 28, 2006

Al Gore: Earth is in 'Full-Scale Planetary Emergency' - space.com

LAS CRUCES, New Mexico—Former U.S. Vice President Al Gore has called for better use of the "space resource" to battle Earth's climate crisis, enlisting entrepreneurial muscle to help solve global issues that threaten the planet's habitability.

Gore said he has long been a fan of faster, cheaper, better approaches that allow the private sector to exploit the space resource "in a responsible and creative, and cost-efficient way."

As an example, Gore spotlighted the competitive and dynamic forces unleashed by the entrepreneurial growth of the Internet.

"We ought to learn that lesson and apply it to space," Gore said. "Because of the environmental climate crisis, we need to speed up the introduction of private companies into the creative exploitation of the space resource."

Gore spoke as part of a Wirefly X Prize Cup Executive Summit 2006 [image], held here Oct. 19, attended by a range of executives, visionaries and space and high-tech leaders.

Serious mistake

Labeling himself as a "recovering politician", the former U.S. Vice President under the Clinton Administration rebuked the recently released space policy by U.S. President George W. Bush.

Gore called the newly issued Bush space policy "a move in the wrong direction" and "a very serious mistake," and urged Summit listeners to analyze the policy "very carefully."

"It has the potential, down the road, to create the kind of fuzzy thinking and chaos in our efforts to exploit the space resource as the fuzzy thinking and chaos that the Iraq policy has created for us in Iraq," Gore explained.

"We need to avoid putting in place a set of policies that end up creating chaos and new obstacles for the creative exploitation of the space resource," he added.

Gore said that the new space policy, in his view, ignores international law and consensus.

"If one nation takes it upon itself to assert its own unilateral definition of what world law should be -- without respect to what the rest of the world thinks about it—that's usually a mistake," Gore told Summit attendees. "Policy matters. Law matters. International law matters."

Humankind's actions

Earth's climate pattern is now being put at risk by humankind's actions, Gore said. "We face what I think should be described as a full-scale planetary emergency."

While aware such a phrase sounds shrill to many ears, Gore added that "unfortunately, I believe it is exactly dead-on accurate."

"We have a climate crisis," Gore said. Humans first became aware of this fact while in space, he said, pointing to the 1968 flight of Apollo 8, when astronaut snapped a photograph showing a distant Earth, in all its beauty and fragility, rising beyond the Moon's barren horizon. The image, one of the most famous in history, caused a dramatic change in the consciousness of humankind, Gore said.

It was also the scientific study of near-Earth planetary neighbors—including Mars and Venus—that spurred the start of the earth sciences, Gore said. "It's still shocking to me that we have more detailed information in some fields about Mars and Venus than we have about Earth."

"Getting a perspective that can give us the ability to really understand and then effectively deal with the climate crisis is from the perspective of space," he said. "And government is not doing it, unfortunately. The private sector can."

Earth: like a business in liquidation

Gore said he expects there to be a "complete reexamination and re-imagining of what space policy should be" after the 2008 election.

Earlier this year, NASA removed the mention of Earth from its mission statement to better match up with the current administration's goal of pursuing human spaceflight to the Moon and Mars.

"[Earth] used to be right up there as one of our most important priorities," Gore said. "I think that if there were a change in administrations and party control…maybe even a new Republican President would reexamine that point and others connected to it."

Gore referenced the view of Herman Daly, an expert on ecological economics, who once said that the planet is being operated like a business in liquidation.

Use of giant sunshades in space to help counteract global climate change—among several space projects dubbed as "geoengineering"—are not favored by Gore.

"In a word, I think it is nuts," Gore told SPACE.com. "If we don't know enough to stop putting 70 million tons of global warming pollution into the atmosphere every day, how in god's name can we know enough to precisely counteract that."

Evacuation route

Pressed on the colonization of space, Gore said that in some future century—maybe sooner—that could be a practical possibility. But he questions the ability of the human race to evacuate the planet, even with ample notice.

"We didn't do a really good job of evacuating the city of New Orleans [due to the onslaught of Hurricane Katrina]," he said.

There's only one Earth, Gore said. "We don't have a spare…we don't have an operating manual."

Our planet has a rising fever, Gore said. "If the crib catches fire you don't say: ‘Hmmm, how fast is that crib going to burn? Has it ever burned before? Is my baby flame retardant?'"

The former U.S. Vice President said his personal cause is to change the public's mind about "this planet crisis" to make it a top priority. The term "crisis" in Chinese is represented by two symbols together, he advised.

Beijing, China/Gland, Switzerland – The world’s natural ecosystems are being degraded at a rate unprecedented in human history, according to a report released today by WWF, the global conservation organization.

WWF’s 2006 Living Planet Report, the group’s biennial statement on the state of the natural world, says that on current projections humanity will be using two planets’ worth of natural resources by 2050 — if those resources have not run out by then. It also confirms the trend of biodiversity loss seen in previous Living Planet reports.

Already resources are depleting, with the report showing that vertebrate species populations have declined by about one-third in the 33 years from 1970 to 2003. At the same time, humanity’s Ecological Footprint — the demand people place upon the natural world — has increased to the point where the Earth is unable to keep up in the struggle to regenerate.

"We are in serious ecological overshoot, consuming resources faster than the Earth can replace them," WWF International’s Director General James Leape said. “The consequences of this are predictable and dire."

"It is time to make some vital choices," he added. "Change that improves living standards while reducing our impact on the natural world will not be easy. The cities, power plants and homes we build today will either lock society into damaging over-consumption beyond our lifetimes, or begin to propel this and future generations towards sustainable living.”

The Living Planet Report, launched in Beijing, China, pulls together various data to compile two indicators of the Earth’s well-being.

The first, the Living Planet Index, measures biodiversity, based on trends in more than 3,600 populations of 1,300 vertebrate species around the world. In all, data for 695 terrestrial, 344 freshwater and 274 marine species were analyzed. Terrestrial species declined by 31 per cent, freshwater species by 28 per cent, and marine species by 27 per cent.

The second index, the Ecological Footprint, measures humanity’s demand on the biosphere. Humanity’s footprint has more than tripled between 1961 and 2003. This report shows that our footprint exceeded biocapacity by 25 per cent in 2003. In the previous report (based on data to 2001), this figure was 21 per cent. The carbon dioxide footprint, from the use of fossil fuels, was the fastest growing component of our global footprint, increasing more than ninefold from 1961 to 2003.

Countries of over a million people with the largest footprint, in global hectares per person, are the United Arab Emirates, the United States of America, Finland, Canada, Kuwait, Australia, Estonia, Sweden, New Zealand and Norway. China comes mid-way in world rankings, at number 69, but its growing economy and rapid development mean it has a key role in keeping the world on the path to sustainability.

Saturday, October 21, 2006

Update on Cassini - NASA/JPL

Tethys has a crater-saturated surface, where older, larger basins have been completely overprinted by newer, smaller impacts. This state is what scientists expect to see on a very old surface, where small impactors have struck more frequently than larger ones over several billion years. Larger impacts were more common events in the early history of the solar system.

This view looks toward the leading hemisphere of Tethys (1,071 kilometers, or 665 miles across). North is up. The great scar of Ithaca Chasma is seen at right.

The view was captured in visible light with the Cassini spacecraft narrow-angle camera on Sept. 25, 2006 at a distance of approximately 449,000 kilometers (279,000 miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 49 degrees. Image scale is 3 kilometers (2 miles) per pixel.

The Cassini spacecraft looks through the dense B ring toward a distant star in an image from a recent stellar occultation observation. These observations point the camera toward a star whose brightness is well known. Then, as Cassini watches the rings pass in front, the star's light fluctuates, providing information about the concentrations of ring particles within the various radial features in the rings.

This view looks toward the unlit side of the rings from about 35 degrees above the ringplane. The star's image is partly saturated, causing the vertical lines that extend up and down.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 26, 2006 at a distance of approximately 543,000 kilometers (338,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 106 degrees. Image scale is about 3 kilometers (2 miles) per pixel.

A world whose mysteries are just coming to light, Enceladus has enchanted scientists and non-scientists alike. With its potential for near-surface liquid water, the icy moon may be the latest addition to the list of possible abodes for life.

The view was acquired about two-and-a-half hours after A Folded Surface, during an encounter with Enceladus (505 kilometers, or 314 miles across).

The image was taken using a combination of spectral filters sensitive to wavelengths of polarized ultraviolet light. The Cassini spacecraft narrow-angle camera acquired the view on Sept. 9, 2006 at a distance of approximately 141,000 kilometers (877,000 miles) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 96 degrees. Image scale is 850 meters (0.5 mile) per pixel.

In this image taken by the Cassini radar system, a previously unseen style of lakes is revealed. The lakes here assume complex shapes and are among the darkest seen so far on Titan.

The lake at the left is reminiscent both in form and scale of the flooded drainage system, Lake Powell in Utah and Arizona. However, the Titan lake has been filled with liquid methane and ethane rather than water. In the lake at right, older terrain may have been deeply cut by river valleys before it was flooded by the embaying lake. For a different radar view from the same flyby see Titan's Great Lakes? .

This radar image was acquired Oct. 9, 2006, and is centered near 80 degrees north latitude, 357 degrees west longitude. It measures about 310 kilometers by 100 kilometers (190 miles by 62 miles). Smallest details in this image are about 500 meters (1,640 feet) across.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries.

An airfield in New Mexico will this weekend host a celebration of space technology: the second annual X Prize Cup games.

The festival is a huge space PR exercise and a showcase for private companies working on space technology. But the main draws are three events that will see space enthusiasts competing for a share of $2.5 million in prize money: the Lunar Lander Challenge, the Vertical Rocket Challenge and the Space Elevator Games.

The lunar lander and vertical rocket competitions are sponsored by NASA, and feed into their ambitions to travel to the Moon. Both contests involve demonstrating an unmanned vehicle that can take off, climb vertically for 50 metres, stay airborne for either 90 (the lander) or 180 (the rocket) seconds, and then land 100 metres from the take-off point.

Experts say the difference in gravity and air pressure between here and the Moon doesn't make too much difference to the design of a lander, and so the games are a good place to test such technology.

Reach for the stars

But the real excitement surrounds the Space Elevator Games, which is split into two $200,000 prizes.

One competition involves making a strong cable of lightweight nanotubes, which is what would be needed to build a real elevator into space. Teams must enter a 2-metre loop of carbon nanotubes no wider than 200 millimetres and no heavier than 2 grams, which will be tested in a tug-of-war. To win, a competitor must have the strongest loop and beat the industry standard of 5.8 Gigapascals by at least 50%.

The real crowd-pleaser is the second half of the elevator games: the climber competition. Entrants must climb a 50-metre ribbon, called the tether, powered only by power beamed from the ground, to cut down on the weight of any fuel or track system.

Last year no team managed to climb the tether. Yet this year, the rules are even tougher. To win climbers must make it to the top carrying a certain amount of weight in 50 seconds or less, and come back down again. "It remains to be seen if anyone can meet all those requirements," says Ted Semon, who is reporting on the games for the official space elevator blog. "I give it at least a 50-50 chance that someone will," he told news@nature.com.

By the end of Wednesday, four out of 12 teams had got through pre-race qualification. Semon says there's no danger of rival teams stealing each other's ideas. "It's much too late to change anything fundamental," he says. "Each team knows what the others are doing by now. Some teams are even sharing equipment."

Just a game?

But isn't a small device shimmying up a 50-metre ribbon very different from the massive reality of a genuine space elevator?

"The climber challenges are set up to directly crack what really needs to be done," says Brad Edwards, who sits on the board of the Spaceward Foundation, which is overseeing the games. In a few years, he predicts, the tether will be attached to a balloon three kilometres up. This will eventually lead to the real thing, he says — a tether stretching to an anchor in orbit.

Mass space travel is a question not of technology, but money, Edward says. Private finance will drive space exploration, he says, and the space elevator is a cheap way for people to buy in.

The material for the tether remains a contentious issue, and there are debates about whether nanotubes can be made strong and light enough to work. Still, says Edwards, there will always be demand for these strong materials, even though space elevators would be a niche part of the market. "It would be driven by tennis rackets and golf clubs."

Tuesday, October 17, 2006

Dancing Asteroid Mapped in Motion - space.com

A near-Earth asteroid is made of two motley parts that dance around each other like a miniature Earth and Moon, a new study finds.

In May 2001, the asteroid 1999 KW4 passed within about 3 million miles (4.8 million km) of Earth. Scientists bounced radar off the asteroid's surface and, by measuring the strength and lag time of the returning signals, were able to calculate many of its physical properties.

The radar imaging shows that Alpha, KW4's larger component, is about one mile (1.5 km) wide and essentially a floating pile of rubble held together by gravity; about 50 percent of it is empty space.

The smaller piece, Beta, is about a quarter of Alpha's size and elongated, like a peanut. Beta orbits Alpha every 17 hours from a distance of about 1.5 miles (2.5 km).

"They are so close together that when one rotates it affects the other's movements," said study team member Daniel Scheeres of the University of Michigan.

Near break-up speed

The findings, detailed in the Oct. 13 issue of the journal Science, also reveal that Alpha is spinning [animation] close to its break-up speed. It makes one complete revolution about once every three hours; if it spun any faster, material from its equator would fly off into space, the researchers say.

As with binary stars, scientists were able to calculate properties of KW4 [image] from a distance based on how its separate parts gravitationally affect each other.

To get the same kind of detailed information from a single-body asteroid, a spacecraft would have to observe it from close orbit. NASA's Near Earth Asteroid Rendezvous (NEAR) Shoemaker spacecraft did just this with Asteroid 433 Eros in 2001, as did the Japanese spacecraft Hayabusa with asteroid Itokawa last winter.

Some of the information gathered from KW4 could be applied to other asteroids, said Eugene Fahnestock, a study team member at the University of Michigan who helped simulate KW4's motions based on the radar data.

"A lot of the things you can tell will inform our general understanding of the internal structure of all asteroids, not just binary asteroids," Fahnestock told SPACE.com.

Propelled by sunlight

Scientists think that KW4's two pieces once belonged to a larger asteroid that broke apart during a perilously close pass by the Earth.

Another possibility is that sunlight shining on the precursor asteroid caused it to spin so fast it broke in two. Because of their odd shapes, asteroids can sometimes act like solar sails, catching sunlight the way sailboats catch wind.

KW4 is classified as a potentially hazardous asteroid (PHA) because it approaches relatively close to Earth compared to other asteroids. However, the latest observations show that there is no chance that KW4 will hit Earth within the next 1,000 years, Scheeres said.

Gene mutation turns girls into boys - Nature

How can a person with two X chromosomes be a man? In more ways than one...

Punchstock

The battle of the sexes continues to rage — right down to the level of our genes.

A gene has now been discovered that, when mutated, turns girls into boys. The finding advances, but also complicates, our understanding of how sex is determined by our genes.

In people, almost all men carry two different sex chromosomes (XY) and women are XX. But there are some (extremely rare) exceptions to this rule. It is possible to have XX men, for example.

This female-to-male sex reversal almost always happens when a certain gene called SRY, usually carried on the Y chromosome, accidentally ends up on the X chromosome inherited from the father.

Other genes have been found to muddle up sexual identity, making the resulting child neither fully male nor fully female. But in most cases of anatomically complete XX men — who have functional testes, but without a Y are infertile — SRY is involved. For this reason, it has long been called the gene that defines 'maleness'.1

But now Giovanna Camerino of the University of Pavia in Italy and colleagues have found another gene that is equally important to the process.

In the family

The team studied a family in which four brothers were each XX. None carried the 'male' SRY gene. Instead, the team reports in Nature Genetics2, they each have a mutation in a gene called RSPO1.

It seems that sex is determined in humans by a cascade of genes. At a crucial junction in this process lies a gene called SOX9, which in males is switched on by SRY, causing testis development. In females, the researchers now suggest, SOX9 might be typically switched off by RSPO1, which, via other genes in the cascade, leads to the development of ovaries. In the brothers, it seems the mutated RSPO1 gene could not fulfil its switching-off role, leaving SOX9 on and leading to male development.

This theory fits with animal studies: mice with two X chromosomes that have their SOX9 expression turned back on form testes.3

Active turn on

The idea stands in contrast to previous theories that said that female development was basically the default that happens in the absence of genes to direct maleness. "What is really important is that suppression of male and induction of female development is an active process," says Andreas Schedl of INSERM, the French National Institute of Health and Medical Research in Nice, who is a co-author on the paper. "RSPO1 clearly plays a key role in this process." The identification of this gene, he says, may be as important to the field as the identification of SRY.

RSPO1 encodes for a protein that is something of a multi-tasker — as well as being a key player in the sex-determining pathway, it also causes all the males in this family to suffer from a skin-thickening condition, and predisposes them to skin cancer. Understanding how it does this might help researchers to confirm its exact role in sex determination.

The next step, say the researchers, is to find out what happens when the RSOP1 gene is knocked out of mice.

Huge Iraqi death estimate sparks controversy - Nature

This bomb in Baghdad reportedly killed at least eight people and wounded 31.

MOHAMMED HATO/AP/EMPICS

Have over 650,000 people, or 2.5% of the population, really died in Iraq as a result of the US-led invasion?

That's the conclusion of a study published in The Lancet this week. But the number has attracted criticism from other researchers who say the result is a major over-estimate, and may have been published for political reasons.

The team behind the figures strongly denies the criticisms. They stress that their methods are well established, and the assumptions they use are validated by other data.

The new number comes from a survey of 1,849 households in 16 regions of Iraq. Teams of questioners organised by the Al Mustansiriya University in Baghdad asked people about household members that had died between January 2002, before the invasion, up to July 2006. They documented 82 deaths in the period before the invasion, and 547 during the conflict.

An extrapolation of this data suggests that the number of deaths per thousand people per year has leapt from 5.5 to 13.3 over that period. Across the whole country, say the researchers, that figure equates to a total of 654,965 more deaths than would have been expected from pre-invasion rates. Just over 600,000 of those were caused by direct violence, the team adds.

The figure is much bigger than previous estimates.

Conflict figures

"I doubt it is large as they say," says Jon Pedersen, a social scientist at Fafo, an independent research centre is Oslo, Norway. Pedersen helped run a United Nations study that concluded between 18,000 and 29,000 people died as a result of violence between the start of the war and May 2004.

He says that violence has become more frequent since his study, but doubts whether the real number can be so much bigger than media reports suggest. Iraq Body Count, a website that collates mortality figures from media sources, puts the current figure at around 45,000.

"We are told about at least 30 to 40 deaths per day just from news reports," says Pedersen. "But 500 per day is very different."

Pederson also points out that the pre-invasion death rate recorded by the Al Mustansiriya team is very low. Figures from the United Nations Children's' Fund from before the war put the number at around 13 deaths per thousand per year. If correct, this suggests almost no increase that can be attributed to the conflict.

But Gilbert Burnham, co-director of the Center for Refugee and Disaster Response at Johns Hopkins University in Baltimore, Maryland and a member of the team that helped design the study, says that neither criticism stands up to scrutiny. He says that pre-war mortality figures from other sources, such the US Central Intelligence Agency, are in line with his data.

Reports of deaths, adds Burnham, were backed up by a death certificate in 92% of the 629 cases they collected. "We recorded what people told us," he says. "We're not making up deaths."

Election countdown

Burnham's group is having also to fight off criticism that its work is somehow political in nature. When he released a previous estimate of Iraqi death tolls in 2004, one team member said that they had wanted to get the result out before the US presidential election, so that "both candidates would be forced to pledge to protect civilian lives in Iraq". The quote was then used by supporters of the Iraq war to brand Burnham's research as politically biased.

With mid-term US elections due next month, Burnham's team is open to the same accusations. Debarati Guha-Sapir, director of the Centre for Research on the Epidemiology of Disasters in Brussels, says that Burnham's team have published "inflated" numbers that "discredit" the process of estimating death counts.

"Why are they doing this?" she asks. "It's because of the elections."

"Absolutely not," replies Burnham. He says that the paper has been delayed and that he hoped to have it out in July or August. "In our team we have some people who are opposed to the war and some who are in favour," he notes. He points out that Iraq has been in the news constantly over the past year, and so his team would have been accused of playing politics no matter when the paper was published.

Distant Planet is Half Fire, Half Ice - space.com

The poet Robert Frost wondered if Earth would wind up a world of fire or ice. Astronomers have discovered that a distant planet is both.

With one side always hot as lava and the other chilled possibly below freezing, Upsilon Andromeda b is a giant gas planet [image] that orbits extremely close to Upsilon Andromeda, a star 40 light-years from our solar system in the constellation Andromeda.

"If you were moving across the planet from the night side to the day side, the temperature jump would be equivalent to leaping into a volcano," said study leader Brad Hansen of the University of California, Los Angeles.

What's cooking

Researchers think Upsilon Andromeda b is absorbing and then immediately radiating heat from its star [animation], so that one side is always hotter than the other. It's also possible the planet is tidally locked to its star the way the Moon is with Earth, so that one side of the planet always faces—and is always heated by—its star.

Upsilon Andromeda b was discovered in 1996. It is what's known as a "hot-Jupiter," a gas giant circles its star in a very tight orbit, in this case 4.6 days. Two other planets also circle Upsilon Andromeda, but farther out.

The new finding, detailed online in the journal Science, marks the first time any kind of temperature variation has been seen across the surface of a planet outside our solar system.

How hot?

Using infrared data collected by NASA's Spitzer Space Telescope, the researchers calculated that temperatures on the sunlit side of the Upsilon Andromeda b were between 2,550 to 3,000 degrees Fahrenheit (1,400 to 1,650 degrees Celsius) but only minus 4 to 450 degrees Fahrenheit (20 to 230 degrees Celsius) on the dark side. Jupiter, in contrast, maintains an even temperature all around.

Spitzer made infrared measurements of the planet at five different points during its orbit and found that its light levels went up and down, depending on whether its sunlit or dark side was facing Earth. From this data, astronomers calculated the temperature difference between the two sides.

"If the planet had just one equilibrium temperature, then all we would get would be a flat line," Hansen explained in a telephone interview.

New thinking

The findings likely apply to other hot-Jupiters as well, the researchers say.

"This observation completely changes our thinking about hot gas giant exoplanets," said study team member Sara Seager of the Carnegie Institution of Washington. "Most astronomers expected them to be more uniformly heated, much like Jupiter. But this planet clearly has a hot side and a cool side."

However, it's possible that Upsilon Andromeda's larger-than-average size has something to do with it, Hansen said. The star around which this planet orbits is slightly hotter and a little bit more massive than the Sun, he said. "How much that has an effect we don't really know."

Galaxy Evolution Explorer detected young, hot, high-mass stars, which are represented in blue, while populations of relatively older stars are shown as green dots. The bright yellow spot at the galaxy's center depicts a particularly dense population of old stars.

Swaths of red in the galaxy's disk indicate areas where Spitzer found cool, dusty regions where stars are forming. These stars are still shrouded by the cosmic clouds of dust and gas that collapsed to form them.

Located 2.5 million light-years away, the Andromeda is our largest nearby galactic neighbor. The galaxy's entire disk spans about 260,000 light-years, which means that a light beam would take 260,000 years to travel from one end of the galaxy to the other. By comparison, our Milky Way galaxy's disk is about 100,000 light-years across.

Titan’s Surface: Dusty Dunes? -

When the Cassini-Huygens probe landed on the surface of Saturn’s largest moon, Titan, last year, it found no evidence of the ethane ocean long thought to cover the satellite’s surface.

Instead, scientists observed dune structures that could be dust-like combinations of ethane and smog particles, according to a new study in the current issue of Nature.

Titan’s dense atmosphere is composed mostly of nitrogen with a small amount of methane. This methane is broken up by the Sun’s ultraviolet light to produce a dense orange-brown smog that hides the satellite’s surface.

Scientists thought that ethane, one of the products of these reactions with the Sun, was abundant enough to have condensed and rained down to form a kilometer-deep ocean across the entire surface of the satellite.

But observations of the surface suggest that it is instead covered by dunes, which Donald Hunten of the University of Arizona thinks could be made of a combination of ethane and smog particles.

Titan's ethane can't condense into liquid rain because “the smog particles grab the ethane before it has a chance to form drops,” Hunten said.

The resulting particles deposit on the moon's surface and pile up to form dunes that might be as deep as several kilometers, Hunten says. The particles would be more like dust than sand though, so Hunten has dubbed them “smust” (a combination of “smog” and “dust”).

Hunten based his proposal for this mechanism on the observed behavior of ethane in Jupiter’s atmosphere, where at certain levels, it condenses onto smog particles.

“Basically, I used Jupiter as the laboratory to show that the ethane is sticking to the particles,” Hunten told Space.com.

“I think there’s a very deep deposit of them on the ground [of Titan], but we can’t confirm that with observations,” he added.

To confirm Hunten’s theory, laboratory experiments would have to be conducted to show that ethane does indeed condense onto the smog particles.